Research
Reveals Link Between Pesticides and Motor Neuron Disease
(Beyond Pesticides, February 3, 2006) Regular
exposure to pesticides may play a role in causing some cases of deadly
motor neuron disease, new Australian research suggests. University of
Sydney scientists have found some patients with the progressive paralyzing
disease have differences in a gene known as paraoxonase, which is involved
in breaking down organophosphate pesticides.

According to neurologist
Roger Pamphlett, PhD, preliminary results from a survey of 900 Australians,
including 300 people with motor neuron disease, suggested regular exposure
to pesticides may increase a person's risk of developing the condition.
The findings are in line with previously done northern hemisphere studies.
(See Daily News
8/19/04).

The Australian researchers
want to confirm the results in a much larger sample of people, including
1,000 motor neuron patients, before they publish their data in a scientific
journal. A National Health and Medical Research Council grant will allow
them to collect information from many more cases during the next five
years.

The scientists have
set up the first DNA bank in the southern hemisphere to investigate
the environmental and genetic influences underlying motor neuron disease,
which usually strikes people aged in their 50s and 60s. Little is understood
about the causes of motor neuron disease which begins with either muscle
weakness, muscle twitching or difficulty in speaking and progressively
leads to paralysis. Most patients die within two to five years of diagnosis.

Associate Professor
Dr. Pamphlett said the DNA bank was the first to cover an entire continent
and was expected to provide new insights into motor neuron disease.

He said the only
treatment at the moment was a drug called riluzole which increased a
person's lifespan by a few months."It does work but the effects
are modest. The treatment can slow the disease down but can't stop it
or reverse it," Dr. Pamphlett said in an interview.

"Our study
seems to be the first hint that paraoxynase could be involved but it
isn't the whole story because it doesn't explain all the cases,"
he said before addressing the Australian Neuroscience Society's annual
meeting in Sydney. The researchers hope that the results of their study
can lead them to more effective treatments for the disease.

Organophosphates
are a widely used class of pesticides, including chlorpyrifos,
diazinon, malathion,
and methyl parathion.
Organophosphates are applied in houses for termite control, in communities
for mosquito spraying, and in agriculture and on golf courses.